Video editing displays white screen
I already had a graphics card driver problem with Blender. The developers helped me out to find out whether the problem is one with the driver.

You should use the opengl32.dll from http://download.blender.org/ftp/sergey/softwaregl/ and place it next to your blender.exe as described by sergey to find out if the problem is your driver. Beware, that Blender might be very slow while using this wrapper dll as everything is done on CPU only without using your graphics card. If it's working this way you know it's a problem with your driver/graphics card.